JPS5914908Y2 - magnetic recording and playback device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a magnetic recording/playback device equipped with a tape end detection device that detects the end of the tape by mechanically detecting the stoppage of rotation of the reel shaft, and in particular returns to playback mode from fast forward or rewind mode. The present invention relates to a magnetic recording and reproducing device that prevents malfunctions in which a tape end detection device is activated when a tape end detection device is activated.

Generally, magnetic recording/playback devices are configured to shift the magnetic recording/playback device to stop mode, eject mode, or reversal mode by detecting the end of the tape. A method of detecting an increase in the number of rotations or a method of electrically or mechanically detecting the stoppage of rotation of the reel shaft has been put into practical use.

However, in the method of mechanically detecting the stoppage of rotation of the reel shaft, when returning from fast forward or rewind mode to playback mode, the tape end detection device is activated even though the tape is not at the end, and the stop or eject mode is activated. This has caused problems such as malfunctions such as the tape running direction being reversed in the case of auto-reverse.

In other words, in fast-forward or rewind mode, the tape is transported at several times the speed as in playback mode, so when returning from fast-forward or rewind mode to playback mode, the tape becomes slack, causing rotation of the supply reel shaft. The tape end detecting device is activated when the time it takes for the tape to become free of slack is longer than the time it takes for the tape end detecting device to operate.

This phenomenon is remarkable in auto-reverse magnetic recording and reproducing devices in which the supply reel axis and the take-up reel axis alternate in the tape running direction.

Therefore, the present invention was developed to eliminate the above-mentioned drawbacks.
To provide a magnetic recording and reproducing device which prevents the tape end detecting device from being activated due to slack in the tape by providing means for disabling the tape end detecting device for a predetermined period when returning from fast forward or rewind mode to playback mode. be.

An embodiment of the present invention will be described below with reference to the drawings regarding an auto-reverse magnetic recording and reproducing device.

1 is a head substrate on which pinch rollers 3, 3' and a magnetic head 4 which are selectively pressed against capstans 2, 2' are mounted, and is arranged to be slidable in the direction of the arrow; The driving force of the motor is transmitted by a mechanism (not shown), and the reel shaft is switched between the supply side and the winding side as appropriate depending on the tape running direction, 6 is a tape end detection device, and the driving force of the motor is transmitted by a mechanism (not shown). The first sliding plate 9 accommodates the chassis shafts 7, 7' in elongated holes 8, 8' and repeats sliding motion in a constant cycle in the front-rear direction, and the guide provided in the chassis in the elongated holes 10 and 10'. The shaft 7 and the shaft 11 implanted in the first sliding plate 9 are stored, overlapped on the first sliding plate 9, and connected to the first sliding plate 9 by a spring 12. a second sliding plate 13 that slides integrally in the front-rear direction;
The first sliding plate 14' is rotatably supported on the second sliding plate 13.
, a detector 14 for detecting rotation stop of the reel shaft 5', the tip of which is configured to come into contact with the reel shaft 5' when the second sliding plates 9, 13 are slid forward; It is pivotally supported on a shaft 11 that is implanted in the sliding plate 9 and projects above the second sliding plate 13,
It also includes a control lever 17 in which the protrusion 15 of the second sliding plate 13 is housed in a guide groove 16.

Therefore, when the reel shafts 5 and 5' are rotating, the first and second
Even if the sliding plates 9 and 13 slide forward and the detector 14 hits the reel shaft 5', it will only rotate as shown in FIG. 2 and will not have any effect, but the rotation of the reel shaft 5' will When the detector 14 stops, the second sliding plate 13 is not rotated as described above when it hits the reel shaft 5'.
is fixed against the bias of the spring 12, and only the first sliding plate 9 is slid as shown in FIG.

Therefore, the control lever 17 pivoted on the shaft 11 on the first sliding plate 9 is connected to the protrusion 15 of the second sliding plate 13 and the guide groove 16.
The lever 18 is rotated and slid counterclockwise by the lever 18, and engages with a reversing lever 18 that reverses the running of the tape, thereby reversing the running of the tape.

19 is a bent piece 21 which is pivotally supported on the chassis by a shaft 20, has one end facing a position where it comes into contact with the detector 14, and forms a tapered side bent above the first sliding plate 9 at the center.
The detector control lever has a protrusion 22 that comes into contact with the lever, and a protruding shaft 23 provided at the other end engages with the cam side 24 of the head substrate 1. A damper effect is provided by the silicone oil, and the head substrate 1 is rotated as the head substrate 1 moves.

Although not shown in the drawings, the pressure of the pinch rollers 3, 3' and the driving of the reel shafts 5, 5' can be selectively switched depending on the tape running direction.

Next, the operation of the present invention having such a configuration will be explained below.

First, in the reproduction mode, the head substrate 1 is slid to the right, so that the pinch roller 3 is pressed against the capstan 2 and the tape is run.

At this time, due to the movement of the head board 1, the detector control lever 19
is rotated counterclockwise as shown in Fig. 1, and the detector 1
The tape end detection device 6 is separated from the moving path of 4.
is not affected by the detector control lever 19 and performs normal detection operation, and when the end of the tape is reached, the reel shaft 5' stops rotating, the detector 14 hits the reel shaft 5', and the control lever 17
is driven to operate the reversing lever 18 and reversing the tape running.

Next, in the fast forward or rewind mode, as the head substrate 1 is slid backward to the left as shown in FIG. 4 by a mechanism (not shown) to release the pressure of the pinch roller 3, the detection The child control lever 19 is rotated by the cam side 24 of the head substrate 1 to a position where its tip faces the movement path of the detector 14.

As a result, the detector 14 is rotated by the detector control lever 19 as shown in FIG. When the central protrusion 22 of the detector control lever 19 comes into contact with the bent piece 21 of the first sliding plate 9, the tip of the detector control lever 19 is rotated to the state shown in FIG.

Thus, in fast forward or rewind mode, the states shown in FIGS. 4 and 5 are alternately repeated.

Next, the operation of switching from the fast forward or rewind mode to the playback mode will be explained.

At this time, the head substrate 1 is immediately slid forward to the right as shown in FIG. 6, and returned to the playback position where the pinch roller 3 is pressed against the cap stand 2, but the detector control lever 19 is Because of the damping effect of the high viscosity silicone oil, it is not immediately rotated and is maintained in the state shown in Figure 6.

As a result, the detector 14 is rotated as shown in FIG. 6, similar to the fast forward or rewind mode, and loses its tape end detection function.

Therefore, even if the tape slackens and the rotation of the reel shaft 5' on the supply side stops when returning from fast forward or rewind mode to playback mode, the detector 14 will not be rotated by the detector control lever 19. , the tape end detection function is lost, and the tape end detection device 6 is never activated.

When the first sliding plate 9 subsequently slides forward, the first sliding plate 9
When the bent piece 21 comes into contact with the protrusion 22 of the detector control lever 19 (see FIG. 7), the detector control lever 19
is rotated counterclockwise against the action of the damper and returned to the state shown in FIG.

The period from when the detector control lever 19 is returned to when the detector 14 normally performs the tape end detection function, that is, the first and second
The duration of one sliding cycle of the sliding plates 9 and 13 is several seconds, and even if the tape slackens, it is sufficiently wound during this time, so that it is first detected by the detector control lever 19 when returning to the playback mode. When the detector 14 whose action has been disabled next hits the reel shaft 5', the reel shaft 5' has been rotated, and the detector 14 is not affected by the detector control lever 19 and is normally operated. Performs tape end detection operation.

In this way, when switching from fast-forward or rewind mode to playback mode, malfunction of the tape end detection device due to stopping rotation of the reel shaft due to slack in the tape is prevented.

As described above, the magnetic recording and reproducing device of the present invention has a reel shaft rotation detector, which keeps the control lever inactive while the reel shaft is rotating, and operates the control lever when the reel shaft stops rotating. In a magnetic recording and reproducing apparatus, the magnetic recording and reproducing apparatus is equipped with a tape end detection device that detects the end of the tape by operating the control lever, and the magnetic recording and reproducing apparatus has a first position in which it is slid forward for a playback mode and a fast forwarding or rewinding position. A control cam is provided on the head board that is set to the second position after sliding backward for the mode, and the control cam follows the movement of the head board from the first position to the second position, and the tape end detection device A detector control lever is provided that is displaced within the movement path of the detector to block the detection action by the detector and is provided with a damper action by oil applied on the chassis, and the head board is moved from the second position to the detector control lever. When returned to the first position, the detector control lever is held in a position that prevents detection by the detector for a certain period of time by its damper action, and then returned to a position where it follows the control cam of the head board. Therefore, even if the tape slacks and the rotation of the reel shaft temporarily stops when switching from fast forward or rewind mode to playback mode,
The detector of the tape end detection device does not detect the stoppage of rotation of the reel shaft, and as a result, it is possible to prevent the tape end detection device from malfunctioning when switching modes as described above, which has an extremely practical effect. It is something.

According to the present invention, the detector of the tape end detection device is controlled by skillfully utilizing the movement of the detector control lever which is given a damper effect by the oil applied on the chassis. The configuration is extremely simple,
It is beneficial.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the configuration of the magnetic recording and reproducing device of the present invention, Figures 2 and 3 are diagrams showing the operation of the main parts of Figure 1, and Figures 4 and 5 are diagrams showing the fast forward or rewind state. The figures shown in FIG. 6 and FIG. 7 are diagrams showing the operation of returning to the reproduction state. 1... Head board, 5, 5'... Reel shaft, 6... Tape end detection device, 9...
...First sliding plate, 13...Second sliding plate, 14.
...Detector, 19...Detector control record

Claims (1)

[Scope of utility model registration request] It has a reel shaft rotation detector, and is configured to keep a control lever inactive while the reel shaft is rotating, and to operate the control lever when the reel shaft stops rotating, and the tape is rotated by the operation of the control lever. In a magnetic recording/playback device equipped with a tape end detection device for detecting the end of a tape, the first position, which is slid forward for playback mode, is set to the second position, which is slid backward for fast forward or rewind mode. A control cam is provided on the head substrate to be detected, and the control cam follows the movement of the head substrate from the first position to the second position, and is displaced into the movement path of the detector of the tape end detection device to detect the tape end. A detector control lever is provided which prevents the detection action by the sensor and is provided with a damper action by oil applied on the chassis, and when the head board returns from the second position to the first position, the detector control lever A magnetic recording/reproducing device characterized in that the magnetic recording/reproducing device is configured such that the magnetic recording device is held in a position where the detection action by the detector is blocked for a certain period of time by its damper action, and then returned to a position where it follows the control cam of the head board.